North Korea sends balloons full of manure and trash over the border to South Korea

SEOUL AND LONDON -- Around 260 air balloons carrying bags of manure and trash have been spotted across South Korea on Wednesday after they were sent over the border from North Korea, according to South Korea's Joint Chiefs of Staff.

The incident reportedly stems from an incident on Sunday when North Korea criticized civic groups in Seoul for sending propaganda leaflets across the border first and subsequently threatened to send filth balloons back to South Korea as a countermeasure, ABC News has learned from the North Korean vice defense minister on the regime's official news outlet.

The regime in North Korea has long complained about this type of action as civic groups have been known to send rice, essential medicine and leaflets accusing the North Korean regime of dictatorship.

The group has been using air balloons for years and reportedly mainly consist of North Korean defectors living in Seoul who are trying to inform the people of North Korea.

The North Korean leader's sister put out a statement Wednesday night referring to the air balloon as "freedom of speech" from the North Korean side and warned of more to come.

"Kim Yo Jong explaining that the filth balloons were sent by the people, and then warning that it will happen again proves that it is the regime that is behind the action," South Korea's Unification Ministry said Thursday, reprimanding North Korea for limiting people's right to express.

This is not the first time North Korea has sent filth balloons to their southern neighbors -- the regime did the same back in 2016 in response to action taken by civic groups performing the same kinds of stunts.

A nationwide warning message in South Korea was issued shortly after the retaliation from the north on Tuesday night and informed citizens to stay away from unidentified balloon remains if or when they come across any.